Listed at 6-foot-2 and 215 pounds, Couplin was used mostly on special teams and had two tackles in eight games for Detroit. The 23-year-old is an undrafted free agent out of William and Mary.
In Buffalo, Couplin fills a roster spot left open after the Bills placed rookie safety Kenny Ladler on the season-ending injured reserve list last week. The Bills (5-3) are coming out of their bye week off and prepare to host Kansas City (5-3) on Sunday.
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